Electrical power generation system

ABSTRACT

An electrical power generation system and method for generating electrical power are provided. The electrical power generation system utilizes a master controller for controlling operation of devices coupled to an AC electrical grid and DC electrical grid based on parameter values associated with a renewable power generator.

BACKGROUND OF THE INVENTION

Power generation systems connected as an electrical mini-grid haveutilized conventional power generators, such as fossil fuel powergenerators, and renewable power generators to supply electrical power toa load. A problem commonly associated with this type of power generationsystem is that the amount of power consumed by loads coupled to theelectrical mini-grid as well as the power generated by the renewablesources connected to the mini-grid cannot be centrally controlled duringoperation. Accordingly, the power generation system is required to haveconnected (running or in stand-by) conventional power generators thathave at least a capacity to produce 100% of the electrical powerconsumed by loads electrically coupled to the mini-grid, irrespective ofwhether the renewable power generators can supply a portion of theelectrical power. Thus, the power generation system utilizes moreconventional power generators than actually needed which increases acost of operating the power generation system and makes the mini-gridoperation not rentable and further impedes its utilization on a largescale.

BRIEF DESCRIPTION OF THE INVENTION

An electrical power generation system in accordance with an exemplaryembodiment is provided. The electrical power generation system includesa first renewable power generator configured to generate a first ACvoltage. The first renewable power generator has a first controllerconfigured to generate a first message having at least a first parametervalue associated with the first renewable power generator. Theelectrical power generation system further includes an AC/DC converterconfigured to convert the first AC voltage to a DC voltage where atleast a portion of the DC voltage is transmitted through a DC electricalgrid. The electrical power generation system further includes a DC/ACconverter configured to convert a portion of the DC voltage from theAC/DC converter to a second AC voltage that is transmitted through an ACelectrical grid. The electrical power generation system further includesa second controller configured to receive the first message. The secondcontroller is further configured to control operation of a first deviceelectrically coupled to at least one of the AC electrical grid and theDC electrical grid based on the first parameter value.

A method for generating electrical power utilizing an electrical powergeneration system in accordance with another exemplary embodiment isprovided. The system includes a first renewable power generator having afirst controller. The first renewable power generator is configured togenerate a first AC voltage. The system further includes an AC/DCconverter electrically coupled between the first renewable powergenerator and a DC electrical grid. The system further includes a DC/ACconverter electrically coupled between the AC/DC converter and an ACelectrical grid. The system further includes a second controlleroperably communicating with the first controller. The method includesgenerating a first AC voltage utilizing the first renewable powergenerator. The method further includes converting the first AC voltageto a DC voltage utilizing the AC/DC converter where at least a portionof the DC voltage is transmitted through the DC electrical grid. Themethod further includes converting a portion of the DC voltage from theAC/DC converter to a second AC voltage utilizing the DC/AC converterthat is transmitted through the AC electrical grid. The method furtherincludes generating a first message having at least a first parametervalue that is associated with the first renewable power generatorutilizing the first controller, that is received by the secondcontroller. The method further includes controlling operation of a firstdevice electrically coupled to at least one of the AC electrical gridand the DC electrical grid based on the first parameter value utilizingthe second controller.

An electrical power generation system in accordance with anotherexemplary embodiment is provided. The electrical power generation systemincludes a first renewable power generator configured to generate afirst DC voltage. The first renewable power generator has a firstcontroller configured to generate a first message having at least afirst parameter value associated with the first renewable powergenerator. At least a portion of the first DC voltage is applied to a DCelectrical grid. The electrical power generation system further includesa DC/AC converter electrically coupled to the first renewable powergenerator. The DC/AC converter is configured to convert a portion of theDC voltage to a first AC voltage that is transmitted through an ACelectrical grid. The electrical power generation system further includesa second controller configured to receive the first message. The secondcontroller is further configured to control operation of a first deviceelectrically coupled to at least one of the AC electrical grid and theDC electrical grid based on the first parameter value.

Other systems and/or methods according to the embodiments will become orare apparent to one with skill in the art upon review of the followingdrawings and detailed description. It is intended that all suchadditional systems and methods be within the scope of the presentinvention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are block diagrams of an electrical power generationsystem in accordance with an exemplary embodiment; and

FIGS. 3-6 are flowcharts of a method for generating electrical powerutilizing the system of FIGS. 1 and 2, in accordance with anotherexemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, an electrical power generation system 10 forgenerating electrical power is illustrated. The electrical powergeneration system 10 generates voltages using renewable power generatorsand conventional power generators that are transferred via DC electricalgrid and an AC electrical grid to load devices. A renewable powergenerator is defined as any power generation device that utilizes arenewable energy source (e.g. wind energy, solar energy, geothermalenergy, hydroelectric energy) to generate electrical power. Anon-renewable power generator is defined as any power generation devicethat utilizes a fossil-fuel (e.g., gasoline, diesel, coal, natural gas)to generate electrical power. The electrical power generation system 10includes a wind turbine power generator 20, a voltage conversion device22, a photovoltaic cell array 24, an DC/AC converter 26, a micro-turbinepower generator 28, a voltage conversion device 30, a non-renewablepower generator 32, a DC electrical grid 34, an AC electrical grid 36,controllable load devices 40, 42, an energy storage device 44, DC/ACconverters 46, 48, AC/DC converters 50, 52, non-controllable loaddevices 54, 56, a master controller 58, a thermal bus 60, a thermalgenerator 62, a thermal energy storage device 64, and a thermal load 66.

The wind turbine power generator 20 is provided to generate an ACvoltage utilizing wind energy. The wind turbine power generator 20includes a local controller 80 and a power generator 82. The powergenerator 82 is configured to generate an AC voltage based upon rotationof a turbine blade (not shown), that is transmitted to the voltageconversion device 22. The local controller 80 is configured to controloperation of the power generator 82 and to calculate a predicted powerlevel of the power generator 82 based on measured operational parametersassociated with the power generator 82. The local controller 80 operablycommunicates with the master controller 58 and is further configured totransmit a message having the predicted power level of the powergenerator 80 to the master controller 58.

The voltage conversion device 22 is provided to convert the AC voltagereceived from the wind turbine power generator 22 to a DC voltage thatis applied to the DC electrical grid 34 and an AC voltage that isapplied to the AC electrical grid 36. The voltage conversion device 22includes an AC/DC converter 84, a capacitor 86, and a DC/AC converter88. The AC/DC converter 84 is electrically coupled between the powergenerator 82 and the capacitor 86. The capacitor 86 is electricallycoupled to the AC/DC converter 84, the DC electrical grid 34, and theDC/AC converter 88. The DC/AC converter 88 is electrically coupledbetween the capacitor 86 and the AC electrical grid 36. Duringoperation, the AC/DC converter 84 converts the AC voltage from the powergenerator 82 into a DC voltage that is stored in the capacitor 86. TheDC voltage from the capacitor 86 is applied to the DC electrical grid34. Further, the DC/AC converter 88 converts the DC voltage from thecapacitor 86 into an AC voltage that is applied to the AC electricalgrid 36.

The photovoltaic cell array 24 is provided to generate a DC voltageutilizing solar energy. The photovoltaic cell array 24 includes a localcontroller 96 and photovoltaic cells 98. The photovoltaic cells 98 areconfigured to generate a DC voltage based upon an amount of solar energyreceived by the photovoltaic cells 98, which is transmitted to the DCelectrical grid 34 and the DC/AC converter 26. The local controller 96is configured to control operation of the photovoltaic cells 98 and tocalculate a predicted power level of the photovoltaic cells 98 based ona measured operational parameters associated with the photovoltaic cells98. The local controller 96 operably communicates with the mastercontroller 58 and is further configured to transmit a message having thepredicted power level of the photovoltaic cells 98 to the mastercontroller 58.

The DC/AC converter 26 is provided to convert the DC voltage receivedfrom the photovoltaic cell array 24 to an AC voltage that is applied tothe AC electrical grid 36. The DC/AC converter 26 is electricallycoupled between the photovoltaic cells 98 and the AC electrical grid 36.

The micro-turbine power generator 28 is provided to generate an ACvoltage. The micro-turbine power generator 28 includes a localcontroller 106 and a power generator 108. The power generator 108 isconfigured to generate an AC voltage that is transmitted to the voltageconversion device 30. The local controller 106 is configured to controloperation of the power generator 108 and to calculate a predicted powerlevel of the power generator 108 based on measured operationalparameters associated with the power generator 108. The local controller108 operably communicates with the master controller 58 and is furtherconfigured to transmit a message having the predicted power level of thepower generator 108 to the master controller 58.

The voltage conversion device 30 is provided to convert the AC voltagereceived from the micro-turbine power generator 28 to a DC voltage thatis applied to the DC electrical grid 34 and an AC voltage that isapplied to the AC electrical grid 36. The voltage conversion device 30includes an AC/DC converter 110, a capacitor 112, and a DC/AC converter114. The AC/DC converter 110 is electrically coupled between the powergenerator 108 and the capacitor 112. The capacitor 112 is electricallycoupled to the AC/DC converter 110, the DC electrical grid 34, and theDC/AC converter 114. The DC/AC converter 114 is electrically coupledbetween the capacitor 112 and the AC electrical grid 36. Duringoperation, the AC/DC converter 110 converts the AC voltage from thepower generator 108 into a DC voltage that is stored in the capacitor112. The DC voltage from the capacitor 112 is applied to the DCelectrical grid 34. Further, the DC/AC converter 114 converts the DCvoltage from the capacitor 112 into an AC voltage that is applied to theAC electrical grid 36.

The non-renewable power generator 32 is provided to generate an ACvoltage by combusting a fossil fuel, such as gasoline, diesel, ornatural gas for example. The fossil fuel power generator 32 includes alocal controller 116 and a power generator 118. The power generator 118is configured to generate an AC voltage by combusting a fossil fuel,which is transmitted to the AC electrical grid 36. The local controller116 is configured to control operation of the power generator 118. Thelocal controller 116 operably communicates with the master controller 58and is further configured to induce the power generator 118 to generatean AC voltage in response to a command message from the mastercontroller 58.

Referring to FIG. 2, the controllable load device 40 is provided toproduce hydrogen gas from water. Further, the controllable load device40 is configured to consume a variable amount of electrical power fromthe AC electrical grid 36 and the DC electrical grid 34. Thecontrollable load device 40 includes a local controller 130 and anelectrolyzer device 132. In the exemplary embodiment, the electrolyzerdevice 132 is electrically coupled to both the AC electrical grid 36 andthe DC/AC converter 46. In an alternate exemplary embodiment, theelectrolyzer device 132 could be coupled to only one of the DC/ACconverter and the AC electrical grid 36. The electrolyzer device 132receives an AC voltage and generates a predetermined amount of hydrogengas utilizing the AC voltage. The local controller 130 is configured tocontrol an amount of electrical power utilized by the electrolyzerdevice 132 when producing the hydrogen gas from water. The localcontroller 130 operably communicates with the master controller 58 andis further configured to induce the electrolyzer device 132 to consume apredetermined amount of electrical power in response to a message havinga commanded power value from the master controller 58.

The DC/AC converter 46 is electrically coupled between the DC electricalgrid 34 and the electrolyzer device 132. The DC/AC converter 46 isprovided to convert a DC voltage on the DC electrical grid 34 to an ACvoltage. The AC voltage at a node 154 produced by both the AC electrical36 and the DC/AC converter 46 is utilized by the electrolyzer device 132to produce hydrogen gas from water.

The controllable load device 42 is provided to purify brackish or saltywater. Further, the controllable load device 42 is configured to consumea variable amount of electrical power from the AC electrical grid 36 andthe DC electrical grid 34. The controllable load device 42 includes alocal controller 134 and a desalination device 136. The desalinationdevice 136 is electrically coupled to the DC/AC converter 48. Thedesalination device 136 receives an AC voltage to drive water pumps (notshown) that purify a predetermined amount of water by removing salt andother impurities from the water. The local controller 134 is configuredto control an amount of electrical power utilized by the desalinationdevice 136 when purifying water. The local controller 134 operablycommunicates with the master controller 58 and is further configured toinduce the desalination device 136 to consume a predetermined amount ofelectrical power in response to a message having a commanded power valuefrom the master controller 58.

The AC/DC converter 52 is electrically coupled between the AC electricalgrid 36 and the DC/AC converter 48. The AC/DC converter 52 is configuredto convert the AC voltage from the AC electrical grid 36 to a DC voltagethat is received by the DC/AC converter 48. The DC/AC converter 48 iselectrically coupled between the AC/DC converter 52 and the desalinationdevice 136. The DC/AC converter 48 is configured to convert a DC voltagereceived from both the DC electrical grid 34 and the AC/DC converter 52at a node 158, to an AC voltage utilized by the desalination device 136.

The energy storage device 44 is provided to either store electricalenergy from the AC electrical grid 36 and the DC electrical grid 34, orprovide electrical energy to the DC electrical grid 34. The energystorage device 44 includes a local controller 150 and a battery array152 comprising a plurality of batteries. The battery array 152 iselectrically coupled to the AC/DC converter 50. The local controller 150operably communicates with the master controller 58. The localcontroller 150 is configured to control whether the battery array 152stores electrical energy from the electrical grids 34, 36 or transferselectrical energy to the electrical grids 34, 36, based on a messagehaving a power storage value received from the master controller 58.

The AC/DC converter 50 is electrically coupled between the AC electricalgrid 36 and the battery array 152. The AC/DC converter 50 is configuredto convert the AC voltage from the AC electrical grid 36 to a DC voltagethat is received by the battery array 152.

The non-controllable load device 54 is electrically coupled to the DCelectrical grid 34. The non-controllable load device 54 is configured toconsume a predetermined constant amount of electrical power from the DCelectrical grid 34 when the device is activated. For example, thenon-controllable load device 54 comprises one or more of an electriclight, an electric motor, a heating element, or the like.

The non-controllable load device 56 is electrically coupled to the ACelectrical grid 36. The non-controllable load device 56 is configured toconsume a predetermined constant amount of electrical power from the ACelectrical grid 36 when the device is activated. For example, thenon-controllable load device 56 comprises one or more of an electriclight, an electric motor, a heating element, or the like.

The AC electrical grid 36 is provided to transfer an AC voltage from theDC/AC converters 88, 104, 114 and fossil fuel power generator 32 to loaddevices. In the exemplary embodiment, the AC electrical grid 36comprises an electrical mini-grid. It should be noted that the ACelectrical grid 36 can operate as a stand-alone electrical mini-grid orcan be electrically coupled to a primary electrical grid. For example,the AC electrical grid 36 could operate as a stand-along electricalmini-grid for distributing power to load devices on an island.

The DC electrical grid 34 is provided to transfer a DC voltage from theAC/DC converters 84, 100, 110, and battery array 152 to load devices. Inthe exemplary embodiment, the DC electrical grid 34 comprises anelectrical mini-electrical.

The master controller 58 is provided to coordinate electrical powergeneration by the wind turbine power generator 20, the photovoltaic cellarray 24, the micro-turbine power generator 28, and the fossil fuelpower generator 32. The master controller 58 is further provided tocontrol electrical power consumption by the controllable load devices40, 42, and either power consumption or power delivery by the energystorage device 44. The master controller 58 operably communicates withthe local controllers 80, 96, 106, 116, 130, 134, and 150. Inparticular, the master controller 58 is configured to generate messageshaving command values that are transmitted to the local controllers 80,96, 106, 116, 130, 134, 150 for controlling operation of the generators20, 24, 28, 32 and devices 40, 42, 44, respectively.

The thermal generator 62 is thermally coupled to the power generator 82,the photovoltaic cells 98, the power generator 108, and the powergenerator 118, to extract heat energy therefrom. The thermal generator62 transfers a fluid through the thermal bus 60 containing the extractedheat energy to the thermal energy storage device 64 and to the thermalload 66. The thermal energy storage device 64 is configured to store theheat energy from the fluid therein.

Referring to FIGS. 3-6, a method for generating electrical powerutilizing the electrical power generation system 10 will now beexplained.

At step 170, the wind turbine power generator 20 generates an ACvoltage.

At step 172, the AC/DC converter 84 converts the AC voltage from thewind turbine power generator 20 to a DC voltage where at least a portionof the DC voltage is transmitted through the DC electrical grid 34.

At step 174, the DC/AC converter 88 converts a portion of the DC voltagefrom the AC/DC converter 84 to an AC voltage that is transmitted throughthe AC electrical grid 36.

At step 176, the local controller 80 determines a first predicted powervalue indicating a predicted amount of electrical power to be generatedby the wind turbine power generator 20 for the DC electrical grid 34 andthe AC electrical grid 36.

At step 178, the local controller 80 transmits a first message havingthe first predicted power value to the master controller 58.

At step 180, the photovoltaic cell array 24 generates a DC voltage thatis applied to the DC electrical grid 34 and the DC/AC converter 26.

At step 184, the DC/AC converter 26 converts a portion of the DC voltagefrom the photovoltaic cell array 24 to an AC voltage that is transmittedthrough the AC electrical grid 36.

At step 186, the local controller 96 determines a second predicted powervalue indicating a predicted amount of electrical power to be generatedby the photovoltaic cell array 24 for the DC electrical grid 34 and theAC electrical grid 36.

At step 188, the local controller 96 transmits a second message havingthe second predicted power value to the master controller 58.

At step 190, the micro-turbine power generator 28 generates an ACvoltage.

At step 192, the AC/DC converter 110 converts the AC voltage from themicro-turbine power generator 28 to a DC voltage where at least aportion of the DC voltage is transmitted through the DC electrical grid34.

At step 194, the DC/AC converter 114 converts a portion of the DCvoltage from the AC/DC converter 110 to an AC voltage that istransmitted through the AC electrical grid 36.

At step 196, the local controller 106 determines a third predicted powervalue indicating a predicted amount of electrical power to be generatedby the micro-turbine power generator 28 for the DC electrical grid 34and the AC electrical grid 36.

At step 198, the local controller 106 transmits a third message havingthe third predicted power value to the master controller 58.

At step 200, the AC electrical grid 36 supplies an AC voltage to thecontrollable load device 40, and the DC/AC converter 46 converts the DCvoltage from the DC electrical grid 34 to an AC voltage that is receivedby the controllable load device 40.

At step 202, the AC electrical grid 36 supplies an AC voltage to theAC/DC converter 52 that converts an AC voltage from the AC electricalgrid 36 to a DC voltage, the DC voltage from the AC/DC converter 52 andthe DC electrical grid 34 being converted to an AC voltage utilizing theDC/AC converter 48 that is received by the controllable load device 42.

At step 204, the DC electrical grid 34 supplies a DC voltage to theenergy storage device 44, and the AC/DC converter 50 converts the ACvoltage from the AC electrical grid 36 to a DC voltage that is receivedby the energy storage device 44.

At step 206, the master controller 58 determines first and secondcommanded power values (P1, P2) for controllable load devices 40, 42,respectively, receiving electrical power from the DC electrical grid 34and the AC electrical grid 36, based on at least one of the first,second, third predicted power values.

At step 208, the master controller 58 transmits fourth and fifthmessages having the first and second commanded power values (P1, P2),respectively, to local controllers 130, 134 of the controllable loaddevices, 40, 42 respectively.

At step 210, the local controllers 130, 134 adjust an amount of powerconsumed by the controllable load devices 40, 42, respectively, based onthe first and second commanded power values (P1, P2), respectively.

At step 212, the master controller 58 determines a power storage value(P3) for the energy storage device 44 based on at least one of thefirst, second, third predicted power values.

At step 214, the master controller 58 transmits a sixth message havingthe power storage value (P3) to the local controller 150 of the energystorage device 44.

At step 216, the local controller 150 adjusts an amount of power eitherstored or delivered by the energy storage device 44 to the DC electricalgrid 34 based on the power storage value (P3).

At step 218, the master controller 58 determines a commanded outputpower value for a non-renewable power generator 32 based on at least oneof the first, second, and third predicted power values.

At step 220, the master controller 58 transmits a seventh message havingthe commanded output power value to a local controller 116 in thenon-renewable power generator 32.

At step 222, the non-renewable power generator 32 generates an ACvoltage that is transmitted through the AC electrical grid 36.

At step 224, the local controller 116 adjusts an amount of power outputby the non-renewable power generator 32 to the AC electrical grid 36based on the commanded output power value.

At step 226, the thermal generator 62 routes thermal energy from atleast one of the wind turbine power generator 20, the photo-voltaic cellarray 24, the micro-turbine power generator 28, and the non-renewablepower generator 32 through a thermal bus 60 to at least one of a thermalload device 64 and a thermal energy storage device 66. After step 226,the method is exited.

The inventive electrical power generation system 10 and method provide asubstantial advantage over other power generation systems. Inparticular, the electrical power generation system 10 utilizes a mastercontroller for controlling operation of devices coupled to an ACelectrical grid and DC electrical grid based on parameter valuesassociated with a renewable power generator.

The above-described methods can be embodied in the form of computerprogram code containing instructions embodied in tangible media, such asfloppy diskettes, CD ROMs, hard drives, or any other computer-readablestorage medium, wherein, when the computer program code is loaded intoand executed by the master controller 58, and local controllers 80, 96,106, 116, 130, 134, and 150.

While the invention is described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalence may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to the teachings of theinvention to adapt to a particular situation without departing from thescope thereof. Therefore, it is intended that the invention not belimited to the embodiment disclosed for carrying out this invention, butthat the invention includes all embodiments falling with the scope ofthe intended claims. Moreover, the use of the term's first, second, etc.does not denote any order of importance, but rather the term's first,second, etc. are used to distinguish one element from another.

1. An electrical power generation system, comprising: a first renewablepower generator configured to generate a first DC voltage, the firstrenewable power generator having a first controller configured totransmit a first message having at least a first parameter valueassociated with the first renewable power generator to a mastercontroller, at least a portion of the first DC voltage being applied toa DC electrical grid; a DC/AC converter electrically coupled to thefirst renewable power generator, the DC/AC converter configured toconvert a portion of the DC voltage to a first AC voltage that istransmitted through an AC electrical grid; a second controllerconfigured to receive the first message from the master controller, thesecond controller further configured to control operation of a firstdevice electrically coupled to at least one of the AC electrical gridand the DC electrical grid based on the first parameter value; and anAC/DC converter electrically coupled to the first device and the ACelectrical grid, the AC/DC converter configured to convert a portion ofthe first AC voltage from the AC electrical grid to a second DC voltagebeing applied to the first device.
 2. The electrical power generationsystem of claim 1, wherein the first renewable power generator comprisesa photovoltaic cell array.
 3. The electrical power generation system ofclaim 1, wherein the first parameter value comprises a first predictedpower value indicating a predicted amount of electrical power to begenerated by the first renewable power generator.
 4. The electricalpower generation system of claim 3, wherein the first device comprises acontrollable load device receiving electrical power from at least one ofthe DC electrical grid and the AC electrical grid.
 5. The electricalpower generation system of claim 1, wherein the first device furthercomprises an energy storage device receiving electrical power from atleast one of the DC electrical grid and the AC electrical grid.
 6. Theelectrical power generation system of claim 5, wherein the secondcontroller is further configured to determine a first power storagevalue based on the first predicted power value, the second controllerfurther configured to generate a second message having the first powerstorage value that is received by the energy storage device, the energystorage device configured to adjust an amount of power stored ordelivered to the DC electrical grid from the energy storage device basedon the first power storage value.
 7. The electrical power generationsystem of claim 5, wherein the energy storage device comprises a batteryarray electrically coupled to the AC/DC converter.
 8. The electricalpower generation system of claim 7, wherein the first device isconfigured to control the battery array to store electrical energy fromat least one of the AC electrical grid and the DC electrical grid or totransfer electrical energy to at least one of the AC electrical grid andthe DC electrical grid based on the first message from the mastercontroller.
 9. The electrical power generation system of claim 1,further comprising a second DC/AC converter electrically coupled to theAC/DC converter configured to convert the second DC voltage to a secondAC voltage.
 10. The electrical power generation system of claim 9,wherein the controllable load device comprises at least one of anelectrolyzer device, a desalination device, an electrical light, and anelectrical motor.
 11. The electrical power generation system of claim 1,further comprising a thermal bus fluidly coupled to at least one of thefirst renewable power generator and a non-renewable power generator, thethermal bus configured to route heat energy generated by the at leastone first renewable power generator and the non-renewable powergenerator to a thermal load.
 12. The electrical power generation systemof claim 11, wherein the thermal bus comprises a conduit configured toroute either a fluid or a gas to the first renewable power generator toextract heat energy from the first renewable power generator and then toroute the fluid or gas to the thermal load.
 13. The electrical powergeneration system of claim 1, wherein the first device is electricallycoupled to at least one of the AC electrical grid and the DC electricalgrid through a power conditioning device.